The Growing Synthetic Utility of Weinreb′s Amide

✍ Scribed by Jaimala Singh; N. Satyamurthi; Indrapal Singh Aidhen

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 90 KB
• Volume: 342
• Category: Article
• ISSN: 1615-4150
• DOI: 10.1002/(sici)1521-3897(200004)342:4<340::aid-prac340>3.0.co;2-1

✦ Synopsis

Since the original discovery of Weinreb , that N-methoxy-N-methyl amides 1, now popularly called as Weinreb amides (WA), cleanly reacted with Grignard reagents and organolithium to produce ketones, these amides have gained wide importance as very effective acylating agents for various organometallic reagents . Even with large excess of organometallics these amides yield exclusively ketones (Scheme 1). No over addition occurs due to effective chelation of metal ion between carbonyl oxygen and N-methoxy oxygen which prevents the collapse of the tetrahedral intermediate 2 until aq acidic work up.